Utility of electrochemotherapy in melanoma treatment

Primary Melanoma: from History to Actual Debates

PURPOSE OF REVIEW

This review describes the long scientific background followed to design guidelines and everyday clinical practice applied to melanoma patients. Surgery is the first option to cure melanoma patients (PTS) at initial diagnosis, since primary cutaneous lesions are usually easily resectable. An excisional biopsy of the lesion, with minimal clear margins, can be obtained in the vast majority of cases. Punch biopsies may be proposed only in case of large lesions located on specific cosmetic or functional areas like the face, extremities, or genitals where a mutilating complete resection would not be performed without prior histological diagnosis.

RECENT FINDINGS

After the histologic confirmation of melanoma, definite surgical excision of the scar and surrounding tissue is planned, to obtain microsatellite free margins. The width of these margins has been identified following the results of several clinical trials and it is either 1 or 2 cm, depending on the Breslow thickness of the primary tumor. Following the latest staging system proposed by the American Joint Cancer commission (AJCC), a sentinel node biopsy (SNB) is usually performed in case of a primary lesion > 0.8 mm thickness or for high-risk thinner lesions, if no evidence of nodal involvement has been identified clinically or radiographically. Surgical management of primary melanoma is well established. There is debate on the optimal surgical margins for 1-2 mm melanomas. There are specific considerations for special primaries (bulky, extremity, mucosal). Sentinel node (SN) evaluation does not improve survival, but is routinely used as staging.

Melanom

Das Melanom ist der gefährlichste Hautkrebs mit der höchsten Sterblichkeitsrate, der schon bei jungen Menschen auftreten kann und seit Jahrzehnten steigende Inzidenz verzeichnet (Jemal et al. 2007; Little et al. 2012). Jährlich erkranken weltweit etwa 137.000 Menschen am Melanom und 37.000 versterben an der Erkrankung (Boyle et al. 2004). Die Inzidenz liegt weltweit jährlich bei 2,3–2,6/100.000 Einwohner (Pisani et al. 2002). In Deutschland beträgt die Inzidenz 19,2/100.000 Einwohner und es verstarben 2711 Betroffene im Jahre 2010 (Statistisches Bundesamt).

Long term effectiveness of electrochemotherapy for the treatment of lower lip squamous cell carcinoma

PURPOSE

Electrochemotherapy (ECT) is a therapeutic approach based on the local application of electrical pulses that permeabilize cell membranes to enhance the uptake of low-permeant chemotherapeutic agents, thus increasing their cytotoxic effects.

MATERIALS AND METHODS

Twenty-one patients with SCC of the lower lip were treated according to the European Standard Operating Procedures of Electrochemotherapy. Bleomycin (15,000 IU/m² body surface area) was administered intravenously over a 1-min period. Eight electrical pulses (amplitude, 1000 V/cm; duration, 100 μs) were generated and delivered at a repetition frequency of 5 kHz. Changes in tumor volume were used to assess treatment response.

RESULTS

Objective response (OR), complete response (CR), and partial response (PR) rates of 100%, 71.4%, and 28.6% respectively were demonstrated following a single session of ECT. ECT was well tolerated, and no adverse events occurred.

CONCLUSIONS

Intravenous bleomycin-based ECT is a safe and effective therapy for SCC of the lower lip. ECT improves the quality-of-life of patients by preserving the function and the aesthetic appearance of the affected area. ECT provides a therapeutic option for elderly and frail patients who, due to their state of health, are not suitable for, or refuse surgical interventions.

Diagnosis and treatment of in-transit melanoma metastases

In transit metastases (ITM) from extremity or trunk melanomas are subcutaneous or cutaneous lymphatic deposits of melanoma cells, distant from the primary site but not reaching the draining nodal basin. Superficial ITM metastases develop in 5-10% of melanoma patients and are thought to be caused by cells spreading along lymphatics; ITM appear biologically different from distant cutaneous metastases, these probably due to a haematogenous dissemination. The diagnosis is usually clinical and by patients, but patients need to be adequately educated in the recognition of this clinical situation. Ultrasound or more sophisticated instrumental devices may be required if the disease develops more deeply in the soft tissues. According to AJCC 2009 staging classification, ITM are included in stages IIIb and IIIc, which are considered local advanced disease with quite poor 5-year survival rates and outcomes of 24-54% at 5 years.² Loco-regional recurrence is in fact an important risk factor for distant metastatic disease, either synchronous or metachronous. Therapy for this pattern of recurrence is less standardised then in most other clinical situations and options vary based on the volume and site of the disease. Definitive surgical resection remains the preferred therapeutic approach. However, when surgery cannot be performed with a reasonable cosmetic and functional outcome, other options must be utilized.^3-6 Treatment options are classified as local, regional or systemic. The choice of therapy depends on the number of lesions, their anatomic location, whether or not these are dermal or subcutaneous, the size and the presence or absence of extra-regional disease.

Immune checkpoint blockade with concurrent electrochemotherapy in advanced melanoma: a retrospective multicenter analysis

Growing evidence suggests that concurrent loco-regional and systemic treatment modalities may lead to synergistic anti-tumor effects in advanced melanoma. In this retrospective multicenter study, we evaluate the use of electrochemotherapy (ECT) combined with ipilimumab or PD-1 inhibition. We investigated patients with unresectable or metastatic melanoma who received the combination of ECT and immune checkpoint blockade for distant or cutaneous metastases within 4 weeks. Clinical and laboratory data were collected and analyzed with respect to safety and efficacy. A total of 33 patients from 13 centers were identified with a median follow-up time of 9 months. Twenty-eight patients received ipilimumab, while five patients were treated with a PD-1 inhibitor (pembrolizumab n = 3, nivolumab n = 2). The local overall response rate (ORR) was 66.7 %. The systemic ORR was 19.2 and 40.0 % in the ipilimumab and PD-1 cohort, respectively. The median duration of response was not reached in either group. The median time to disease progression was 2.5 months for the entire population with 2 months for ipilimumab and 5 months for PD-1 blockade. The median overall survival was not reached in patients with ipilimumab and 15 months in the PD-1 group. Severe systemic adverse events were detected in 25.0 % in the ipilimumab group. No treatment-related deaths were observed. This is the first reported evaluation of ECT and simultaneous PD-1 inhibition and the largest published dataset on ECT with concurrent ipilimumab. The local response was lower than reported for ECT only. Ipilimumab combined with ECT was feasible, tolerable and showed a high systemic response rate.

Effectiveness of electrochemotherapy after IFN-α adjuvant therapy of melanoma patients

Background

The combination of electrochemotherapy with immuno-modulatory treatments has already been explored and proven effective. However, the role of interferon alpha (IFN-α) adjuvant therapy of melanoma patients and implication on electrochemotherapy effectiveness has not been explored yet. Therefore, the aim of the study was to retrospectively evaluate the effectiveness and safety of electrochemotherapy after the previous adjuvant treatment with IFN-α in melanoma patients.

Patients and methods

The study was a retrospective single-center observational analysis of the patients with advanced melanoma, treated with electrochemotherapy after previous IFN-α adjuvant therapy. Five patients, treated between January 2008 and December 2014, were included into the study, regardless of the time point of IFN-α adjuvant therapy.

Results

Electrochemotherapy of recurrent melanoma after the IFN-α adjuvant therapy proved to be a safe and effective treatment. Patients with one or two metastases responded completely. Among patients with multiple metastases, there was a variable response rate. In one patient all 23 metastases responded completely, in second patient more than 85% of all together 80 metastases responded completely and in third patient all 5 metastases had partial response. Taking into account all metastases from all patients together there was an 85% complete response rate.

Conclusions

The study showed that electrochemotherapy of recurrent melanoma after the IFN-α adjuvant therapy is a safe and effective treatment modality, which results in a high complete response rate, not only in single metastasis, but also in multiple metastases. The high complete response rate might be due to an IFN-α immune-editing effect, however, further studies with a larger number of patients are needed to support this presumption.

A rare case of anal porocarcinoma treated by electrochemotherapy

We report the case of an old woman with an eccrine porocarcinoma unusually localized in the perianal area treated by electrochemotherapy, a new technique, emerging as a very effective local treatment of different skin metastases and selected primary tumors. Electrochemotherapy was performed taking into account patient wishes and refusal of demolitive surgery. The electrochemotherapy treatment was well tolerated by the patient, it gave an excellent clinical response and a complete clinical regression with no sphincter dysfunction and signs of relapse observed during follow-up. The case is of particular interest for the exceptional localization of porocarcinoma for the first time treated by electrochemotherapy in this area. Electrochemotherapy could be considered as an alternative option for selected cases of cutaneous tumors.

Locally enhanced chemotherapy by electroporation: clinical experiences and perspective of use of electrochemotherapy

Electroporation is used to enhance drug diffusion and gene delivery into the cytosol. The combination of electroporation and cytotoxic drugs, electrochemotherapy (ECT), is used to treat metastatic tumor nodules located at the skin and subcutaneous tissue. The objective response rate following a single session of treatment exceeds 80%, with minimal toxicity for the patients. The efficacy of ECT in the bone and visceral metastasis is currently investigated, and Phase II studies have been completed. ECT has been used to treat skin primary tumors, except melanoma, and is under investigation for locally advanced pancreatic cancer. Early evidence suggests that treatment of tumor nodules with ECT recruits components of the immune system and eliciting a systemic immune response against cancer is a challenging clinical perspective. Considering the proven safety in several different clinical applications electroporation should be viewed as a clinical platform technology with wide perspectives for use in ECT, gene therapy and DNA vaccination.

Electrochemotherapy is effective in the treatment of rat bone metastases

Bone metastases impair general health status, quality of life and survival of patients. Electrochemotherapy (ECT), which combines electroporation (EP) and the administration of anticancer drugs, has been recently introduced into clinical practice for the local treatment of solid tumours. In the present study, the ability of EP with bleomycin (Bleo) to induce MRMT-1 rat breast cancer cell death was investigated in vitro. Then, an in vivo model for bone metastases was set up by the inoculation of MRMT-1 cells in rat proximal tibia. 7 days after tumour induction the animals were treated with Bleo, EP, Bleo followed by EP (ECT), or left untreated. ECT eliminated the tumour in 6 out of 8 (75 %) treated metastases. Radiological evaluation showed that the Honore score in ECT-treated animals was significantly lower when compared with the other groups (p < 0.0005) and not significantly different from healthy controls. Bone morphology in ECT-treated animals, evaluated by histological and microtomographical analyses, showed intact cortical and trabecular bone structure with new bone apposition. Histomorphometric evaluation showed that ECT-treated metastases had significantly higher bone volume, trabecular number, trabecular thickness and bone mineral density compared with those of untreated metastases (respectively p < 0.0005 for BV/TV, Tb.N and BMD; p < 0.05 for Tb.Th) or metastases treated with Bleo (p < 0.05 for BV/TV, Tb.N, p < 0.005 for BMD) or EP (p < 0.005 for BV/TV, Tb.N; p < 0.0005 for BMD). These findings suggest that early ECT treatment of bone metastases is minimally invasive, safe and effective, thus providing pre-clinical evidence for its use in the treatment of human bone metastases.

Surgical treatment of primary melanoma

The incidence of primary cutaneous malignant melanoma (MM) has been rapidly growing during the last decades with only a small rise in overall mortality. MM accounts for most of the deaths from skin malignancies due to its metastatic potential. However, early detection and wide surgical excision with histologically negative margins are nearly always curative for patients without micrometastatic disease. Although nonsurgical treatments have been increasingly used in recent years, surgery with standardized margins remains the only curative treatment modality for primary cutaneous MM. There are some special locations (e.g., the ear, nose, eyelid, genitalia, hand, or foot) where standardized wide surgery can not be completely achieved either for lack of tissue, ill-defined lesions, or cosmetic and functional reasons. Thus, skin surgeons dealing with these MMs should be well versed in new technologies such as confocal microscopy for the presurgical assessment of ill-defined lesions or the promising electrochemotherapy for nonsurgical tumors. Furthermore, a multidisciplinary melanoma team and a well-trained and experienced surgeon are mandatory to deal with these "out-of-the-guidelines" melanomas.

Cationic lipid:DNA complexes allow bleomycin uptake by melanoma cells

Bleomycin is a chemotherapeutic agent barely diffusible through the plasmatic membrane. We evaluated DNA/cationic lipids complexes (lipoplexes) as mediators of its uptake in four spontaneous canine melanoma derived cell lines (Ak, Bk, Br and Rkb). Cell survival after lipofection plus or minus bleomycin was determined by the acid phosphatase method and the cellular uptake of lipoplexes, carrying the E. coli β-galactosidase gene, was evidenced by SYBR Green I staining. The four cell lines resulted sensitive to the bleomycin/lipoplexes system in both spatial configurations. Survival rates values were lower than 20% in monolayers of the four tested lines and lower than 30% in three lines (Ak, Bk and Rkb) when grown as spheroids. The sensitization to bleomycin depended on lipoplexes in Ak and Rkb while Bk (in both spatial configurations) and Br (as monolayers) were sensitive to bleomycin alone. Although some degree of sensitivity to bleomycin was induced by cationic lipids alone in Ak and Rkb monolayers, the maximal bleomycin effects appeared in the presence of lipoplexes. The sensitization was independent of transcriptional activity. The co-administration of lipoplexes diminished bleomycin IC50: 10-fold in Ak and Rkb monolayers; and sensitized the Ak and Rkb resistant spheroids. The bleomycin cytotoxic effects depended on lipoplexes concentration and diminished when cells were incubated at 8°C. Our results suggest that lipoplexes sensitize cells to bleomycin, increasing its uptake by an active transport mechanism, such as endocytosis. The bleomycin/lipoplexes system appears as a promising combination of chemotherapy and non-viral cancer gene therapy.

Network for development of electroporation-based technologies and treatments: COST TD1104

Exposure of biological cells to a sufficiently strong external electric field results in increased permeability of cell membranes, referred to as "electroporation." Since all types of cells (animal, plant and microorganism) can be effectively electroporated, electroporation is considered to be a universal method and a platform technology. Electroporation has become a widely used technology applicable to, e.g., cancer treatment, gene transfection, food and biomass processing and microbial inactivation. However, despite significant progress in electroporation-based applications, there is a lack of coordination and interdisciplinary exchange of knowledge between researchers from different scientific domains. Thus, critical mass for new major breakthroughs is missing. This is why we decided to establish cooperation between research groups working in different fields of electroporation. Cooperation in Science and Technology (COST), which funds networking and capacity-building activities, presents a perfect framework for such scientific cooperation. This COST action aims at (1) providing necessary steps toward EU cooperation of science and technology to foster basic understanding of electroporation; (2) improving communication between research groups, resulting in streamlining European research and development activities; and (3) enabling development of new and further development of existing electroporation-based applications by integrating multidisciplinary research teams, as well as providing comprehensive training for early-stage researchers. Results of this COST action will provide multiple societal, scientific and technological benefits from improving existing electroporation-based applications to adding new ones in the fields of medicine, biotechnology and environmental preservation.